mediatek: filogic: bpi-r4: set netdev-name for sfp ports

mediatek: filogic: bpi-r4: set netdev-name for sfp ports

Sets openwrt,netdev-name for the gmac nodes in the dts of BPI-R4 which
correspond to the two sfp slots. By default they are automatically
named as eth1 and eth2 in bad order, however 'SFP1-WAN' and 'SFP2-LAN'
are printed on the PCB and the official metal case has labels 'SFP-WAN'
and 'SFP-LAN'. Thus, label the ports accordingly to match the
board/case labels.
The COMPAT_VERSION is increased to denote that configuration has to be
adjusted manually.

Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>